This invention generally relates to water delivery systems and, more specifically, to a temperature controlled system which includes a water conservation by-pass circuit.
While most people have long taken water for granted, many are learning to recognize that this is a precious resource which must not be wasted. Many regions in this country and in other countries have chronic water shortage problems, and massive and costly water conservation plans are implemented to conserve this resource. Many localities, furthermore, in order to enforce conservation, mandate that water delivery to businesses and homes be metered so that end users pay for the water that they use. For these reasons, water is an important resource and must always be conserved and not wasted needlessly.
One example where considerable waste has consistently occurred, and not without at least a reasonable basis therefor, is the water that is wasted when a shower is first turned on. Because there is a considerable amount of "standing" water in the hot water pipes or lines between the hot water heater and the shower nozzle, it is clear that the water that is initially dispensed from the shower will be cold water, regardless of the setting of the shower temperature control valve. Until the cold water has been depleted from the hot water line and new hot water replaces it, the temperature of the water coming out of the shower head is totally beyond the control of the user. For this reason, users typically turn the shower on and allow the water to simply go down the drain until the standing water has been depleted and the warm water starts to come out of the shower nozzle. Only at that time, can the temperature be adjusted to the desired temperature and the shower be used. The water that is initially discarded represents a significant waste of water, particularly when considering the tens of millions of showers that are taken daily. Such needless waste of water is costly not only to the various localities and water distribution systems but also to the user who, one way or another, is charged for the water. Also, the end user is currently needlessly paying for heating of water that is discarded until such time that the water discharged by the nozzle attains a sufficiently high desired temperature. Therefore, even warm water is allowed to go down the drain until the desired temperature has been attained.
Although the aforementioned condition is one that has existed undoubtedly since showers were first invented, very little has been done to ameliorate this problem.
In U.S. Pat. No. 2,983,487, a liquid supply system is disclosed for providing water at a desired temperature in photo-finishing processes, where the system checks the temperature of the water entering into the system and seeks to maintain the temperatures so that the mixed water at the outlet will be within a desired range. However, the emphasis is on maintaining a desired dispensing temperature, as opposed to the conservation of water until such time that the desired temperature has been achieved.
In U.S. Pat. No. 3,091,393, a fluid amplifier mixing control system is disclosed to adjust the temperature by the use of an oscillating member. However, water is not redirected back to the source. In U.S. Pat. No. 3,958,555, a fluid supply system includes a fluid blending valve which discharges blended liquid into a recirculation pipeline. Fluid is drawn off and at least a portion of the recycled liquid is fed to a heat exchanger to insure that the temperature of the recycled liquid is maintained at a desired value. A thermostatic control valve is provided responsive to the recycled liquid temperature which cooperates with the exchange to maintain the recycled liquid temperature at a desired value. The system, therefore, is primarily concerned with maintaining water temperature as opposed to water conservation during initial turn on of the system.
In U.S. Pat. Nos. 4,249,695 and 4,294,402, control devices for heaters are disclosed which are concerned with conserving heat as opposed to saving water.
In U.S. Pat. Nos. 4,322,031 and 4,330,081, water controls are disclosed for controlling the temperatures for washing machines and sanitary mixing valves, and have the same drawbacks as the previously described systems.
In view of the above art, it is clear that conservation of water has not been a primary and foremost factor in connection with heated water dispensing systems.